The field of this invention is biopolymeric arrays.
xe2x80x9cBiochipsxe2x80x9d or arrays of binding agents, such as oligonucleotides, cDNA and peptides, and the like have become an increasingly important tool in the biotechnology industry and related fields. These binding agent arrays, in which a plurality of binding agents are deposited onto a solid support surface in the form of an array or pattern, find use in a variety of applications, including gene expression analysis, drug screening, nucleic acid sequencing, mutation analysis, and the like.
In array-based assays in which an array of binding agents is employed, the array is typically contacted with a fluid sample that is suspected of containing the analyte(s) of interest. After a sufficient incubation period with the sample, often at elevated temperatures, the array is typically washed with at least one wash agent to remove the unbound sample from the array and any material that may have non-specifically bound to the array surface. As such, array based procedures typically require a number of different steps including fluid introduction, incubation, washing, etc.
In array hybridization procedures, it is critical that the sample is evenly applied across the array and that the array does not dry out during the hybridization process, as such drying-out can damage the array.
Initially, array based hybridizations simply took place on a microscope slide, typically the slides were covered with a cover slip to help distribute the sample over the array surface and keep the slide from drying out. However, this method was labor-intensive and inefficient. To address these problems, hybridization chambers were developed to simplify the process and increase the efficiency thereof. Such chambers range from a simple chamber which merely functions as a depository for the array during hybridization to chambers that have some or all of the hybridization process automated.
For example, U.S. Pat. No. 6,114,122 discloses an automated hybridization station having a fluid delivery system associated with it. The ""122 patent discloses a package for housing an array during hybridization where the array substrate is attached to the body of the cartridge, preferably with an adhesive. Also, U.S. Pat. No. 5,958,760 discloses an automated apparatus having a chamber which uses a silicon rubber gasket or O-ring to substantially seal the chamber for processing a glass slide support therein. Further, U.S. Pat. No. 5,595,707 discloses an automated biological reaction apparatus having a carousel slide support which supports a plurality of slide supports thereon to increase the quantity of slides which can be processed concurrently. The ""707 patent further discloses that the biochemical reaction is carried out under a layer of an evaporation inhibiting liquid to minimize dehydration.
Although effective, there are drawbacks associated with each of the above techniques. For example, sealing means such as adhesives, gaskets or O-rings used in the process may result in a flawed array surface or unreacted sections of the array due to the adhesive, gasket or O-ring contacting the array and interfering with the even distribution of the sample over the array surface. Similarly, use of an evaporation inhibiting liquid may create an un-even distribution of the liquid causing evaporation of portions of the array and ultimately un-reacted sections. In addition, the device disclosed in the ""122 patent is limited in that it must be used with specific array formats, and therefore is not suitable for use with all of the different array platforms currently employed by those of skill in the art.
As such, there is continued interest in the development of new devices for array-based hybridizations and methods of using the same. Of particular interest would be the development of an array-based hybridization chamber, and methods of use thereof, that provides for the even distribution of a sample over an array surface, substantially prevents dehydration of the array surface during the hybridization process, is simple to use, efficient, at least partially automated and can be used with the multitude of different array formats currently employed in the art.
Patents and patent applications of interest include: U.S. Pat. Nos. 5,552,087; 5,595,707; 5,650,327; 5,654,199; 5,654,200; 5,958,760; 6,114,122; and 6,238,910.
Also of interest are the webspaces located at the URLs of the world wide web which are at agilent.com; affymetrix.com; apbiotech.com and genomicsolutions.com.
Array hybridization devices and methods for their use are provided. The subject devices are characterized by having a substantially planar bottom surface, a cover, at least one fluid port and at least one adjustable spacing element for adjusting the spacing between an array and the bottom surface. In using the subject devices, an array is placed on the at least one adjustable spacing element in the chamber and the space between the array and the bottom surface is adjusted by moving the at least one adjustable spacing element. The adjusted array is contacted with at least one biological sample introduced into the chamber. The subject inventions find use in a variety of array-based applications, including nucleic acid array hybridizations.